Impact tamping roller



Dec. 17, 1963 F. J. DAVIS 3,114,305

IMPACT TAMPING ROLLER Filed Aug. 31, 1960 4 Sheets-Sheet 1 Jay 1.

INV EN TOR l BY 4/ 1/ 162%: ATTORNEY) Dec. 17, I963 F. J. DAVIS 3,114,305

IMPACT TAMPING ROLLER Filed Aug. 31, 1960 4 Sheets-Sheet 2 m; IIIIIIIIIIIIIIIl/Illll.922E? VIIIIIIIIIIIIII/IIIII/l"I516 6d a j I II I "H 3 0 0 6 cl INVENTOR iksasle/c d. DA v/s ATTORNEY) Dec. 17, 1963 F. J. DAVIS IMPACT TAMPING ROLLER R 0 H w; m Y m a m m w Q J n w Q\fi.. ll vr/Av \Q\\.\ hm? k m #9 k M g a F n 1 Q M N R R. 5 R. R h m l 9 u w nlhu 41 J m. K Q m M. Q\ R.

ATTORNEY j Dec. 17, 1963 Filed Aug. 31," 1960 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII F. J. DAVIS IMPACT TAMPING ROLLER 4 Sheets-Sheet 4 INVENTOR FkEDER/sk J 0/) W8 ATTORNEY} United States Patent 3,114,305 IMPACT TAMPWG RULLER Frederick J. Davis, 468% S. Lipan St, Englewood, Colo. Filed Aug. 31, less, Ser. No. 53,199 9 Claims. (Cl. 945i This invention relates to improvements in roller type impact taniping machines.

The tamping of earth by roller type machines is well known, but there are disadvantages of conventional roller type tamping machines because of the excessive power required to propel the roller and its slow speed. t is a purpose of the present invention to apply a principle of pneumati activation of tamping feet whereby the Weight of the roller can be reduced and drag of stationary feet in the soil eliminated with an increase in speed of operation.

When used as structural material, soil is usually placed in relatively thin layers and each layer is then compacted or densiiied to a condition approximating some laboratory standard. Design of the structure is based on the engineering proper ies developed in the soil when compacted by the laboratory standard method. In earth-Work structures such as dams, it is imperative that, in addition to obtaining good density, individual layers of soil be well bonded and keyed to each succeeding layer so that the water cannot find an easy path of percolation between layers. The tamping (sheepsfoot) roller has been found to be most satisfactory for this type of compaction, acting upon layers of earth usually placed in six inch compacted thicknesses.

For compacting earth fills which act as water barriers, particularly high earth dams, smooth drum rollers and rubber-tired rollers have certain disadvantages which are unacceptable to many engineers. rimary among these objections is a suspected anisotropy or stratification induced by the rollers. The principal desirable characteristics of the tamping (sheepsfoot) roller are: (a) compaction of each layer from the bottom, thus achieving isotropy throughout the layers; (1)) mixing of the materials as an inherent part of its action, thus achieving additional isotropy within the layer; and (c) effectiveness in producing uniform and satisfactory results proved by long usage. The principal disadvantage of present tamping roller is the excessive power required to propel the roller and its slow speed. As the normal type of camping roller is pulled along, only a few tamping feet are vertical at any given time, while three or more rows of long tam-ping feet are constantly being pulled out of the soil. Consequently, a tremendous draw-bar horsepower is required to ofiset the excessive drag created by the action of the tamping feet in the soil and the high static weight of the roller required for compaction. With this in mind it is a further object of this invention to provide a compact type of tamping roller with pneumatically, or hydraulically actuated tamping pistons and feet, capable of worxing speedily over a given area; the improved machine requiring less weight for compactive effort than for conventional devices; less draw-bar horsepower, and fewer passes over a given area.

Gther objects and advantages of this invention will be apparent during the following detailed description.

In the accompanying drawings, forming a part of this specification, and wherein similar reference characters designate corresponding parts throughout the several views:

his

FIGURE 1 is a plan View of the improved machine, of dual roller drum type, in which one roller drum is shown in full plan and the other roller drum in cross section.

FIGURE 2 is a side elevation of the machine of FIG- URE l.

*IGURE 3 is a transverse cross sectional view taken through one of the rollers of the machine, substantially on the line 33 of FEGURE 1.

FIGURE 4 is a developed view of the roller drum showing the relative spacing and arrangement of tamping feet and the locations of access plates.

FIGURE 5 is an enlarged fragmentary cross sectional view taken along one of the drum axles, showing the frame bearing mountings and the mounting of the tamping equipment.

FIGURES 6 and 7 are fragmentary cross sectional views taken substantially on the respective lines 6% and 7-7 of FIGURE 5.

FlGURE 8 is a fragmentary cross sectional view taken substantia ly on the line 8-$ of FIGURE 7.

FIGURE 9 is a fragmentary enlarged cross sectional view taken through the structure of one of the tampmg devices, showing the tamping piston, air rings, axle, valve means, and means for actuating the valve.

FIGURE 19 is an enlarged fragmentary cross sectional view taken substantially on the line Eli-1% of FIGURE 9 showing certain valve means for actuating the tamper with portions omitted.

In the drawings, wherein for the purpose of illustration is shown only a preferred embodiment of the invention, the letter A may generally designate the impact roller type tamping machine. It may consist of a towing frame B supporting a stationary axle or axles C, and tamping rollers D each of which may comprise a drum E and tamping equipment F. The tamping feet of rollers D are preferably actuated by an air compressor G, although hydraulic means can be used if found desirable.

The towing frame B rotatably supports one or more of the rollers D. The drawings show a frame supporting two rollers D. To that end such frame may comprise outer side beams l5 and in and intermediate beams 17' and i8, complementary to beams 25 and 16 respectively. The beams 15 and l6 are forwardly connected by diagonal frame beams 2i and 211 which are also connected to the closely spaced intermediate beams 17 and 18; the latter projecting forwardly and there being provided with a tractor hitch 22. Front cross beams 23 may be provided for connecting the intermediate beams 17 and I8 with the outer side beams. At the rear of the frame other cross beams 2e are provided. A rear hitch 27 may be provided, if found desirable. These beams may be of angle, tubular, or any type of material capable of receiving the forces imposed thereon.

Each of axles Q is preferably constructed out of square cross sectional stocx, having at its end squared portions 28 which may be secured by brackets 29 bolted to the longitudinal frame beams, such as shown for the beam 15 in FIGURE 6. Thus the axles are mounted in stationary position against rotation upon the frame B. Adjacent to the squared portions and inwardly therefrom the axles C are each provided with cylindrical shaped bearing spindles 3d upon which are rotatably mounted the roller D. Between the spindle portions 3th the axle C is provided with a series of grooves 31 forming cylindrical portions 32 upon which air rings of the tamping equipment are rotatably mounted, to be subsequently described in detail. Each axle C is longitudinally provided with a passageway 35, through which the actuating fluid passes. The passageway 35 may open at each end into a screw threaded socket 3-6 into which the fluid conducting hose 37 may be coupled as at 38 shown in FIGURE 8. The opposite socket 36 of the passageway 35 may be closed by a plug 39. At the locus of the air ring bearing portions 32 there are radially disposed air ducts or ports 45, shown best in FIGURE 9, which open at the air ring bearing portions 32 and also communicate with the passageway 35. The drawings show four of these ports for each air ring bearing portion 32, but more or less may be provided if found necessary. There purpose is to feed the actuating fluid into the air ring.

Each roller assemblage D comprises a metal drum E which is of a weight sufficient to provide the type of tarnping desired. For a five foot diameter five feet long drum I have found that one inch steel plate material suffices for the cylinder portion 45 of the drum. These cylinder portions 45 are closed by end walls 46 and 47; the end walls 46 and 4-7 being formed of semi-circular segments flanged at 43 and 49 and bolted together at 56 Centrally, the walls 46 and 47 are provided with hearing segments 50 which may bear directly or by anti-friction bearing means on the axle portions 30, as shown in FIGURE 5. These bearing segments may be welded as at 51 to the segments of the end walls 46 and 47.

For the particular roller D, shown in the drawings, there are eight series of tampers arranged annularly about the axle C; each series including 14 individual tamping members and the actuating means therefor.

The structure of the tamping feet, pistons and the actuating means .therefor is identical for each tamper and therefore but one will be described. To that end, each tamping head 60, which is of cylindrical formation is provided with a piston head 61. It is reduced annularly at 62 (see FIGURE 9) to provide space for a spiral compression spring 63. The latter normally bears at its outer end against a piston stop ring 64- which is welded or otherwise secured within the piston cylinder 65. The cylinders 65 are each provided with a tamping head and piston receiving passageway 66 therein opened at its outer end. The cylinders are provided with sealing rings 67 bearing against the tarnping heads 63. The cylinders 65 are provided with drum attaching flanges 68 (see FIG. 3) welded thereto at 69. These flanges 63 are detachably connected as by bolts 7% either directly to the cylindrical drum 45 or to certain access plates 76 which in turn are bolted as at 77 upon the drums. The purpose of the access plates 76 is to insure that, for maintenance purposes, the drum 45 can be opened circumferentially to permit access to the tamping members and their associated details. It will be noted from FIGURES 3 and 4 that three sets of access plates are provided circumferentially upon the drum 4-5. It is of course immaterial whether the cylinders 65 are secured directly to the drum 45 or indirectly to the drum through the access plates, because the latter in turn are bolted at 77 to the drum itself.

The cylinders 65 are arranged with fourteen in each series, as shown in FIGURE 3 and they are radially positioned.

The valve means for admitting and exhausting the actuating fluid through the cylinders 65, as shown in FIGS. 9 and 10, includes a valve housing 86} which may be bolted at 81 to each cylinder 65 and which has an air chamber 82. An inlet opening 83 opening to chamber 82 communicates with an intake port 84 opening to the inner end of the piston cylinder chambers 66, above the piston head 61. Likewise an outlet opening 85 is provided in the Valve housing communicating with an exhaust port 86 opening to the cylinder chamber 66; the outlet opening 35 opening to the atmosphere for exhausting the fluid from the cylinder, as shown in FIGURE 9.

The air rings are of cylindrical box-shaped construction and rotatably bear upon the axle portions 32. The chambers 91 thereof receive air from the ports 4!). The air ring 99 has its annular shell provided with passageway providing nozzles 93 which open to the chamber 91; the nozzles 93 radially projecting from the air ring outer wall for attachment of flexible hose lengths 94 thereto. An elbow or coupling 95 is connected to each valve housing 86 and provided with a passageway for admitting air from the hose 94 into the air chamber 32.

A valve 1% is reciprocally mounted in a passageway of the valve housing 89. It has a valve stem 10} Jhich is slidably mounted in a sleeve 102 integral with the valve housing; the sleeve 102 extending radially inwardly toward the axle C and there being detachably secured by a bracketing structure 132 to an outer wall of the air ring 9%. The stem 161 extends radially in the direction of the axle C and in a path to be moved against a conical shaped cam 165, shown best in FIGURE 10. The cams 105 are mounted on the lowermost side of the squared portions of the axle C; preferably detachable at 1%. Cams 105 actuate the valve stems 1G1 and valves mt) into position for flow of the actuating fluid into the cylinder chambers, when the t amping heads are in lowermost vertical position. It is thus apparent that for each of the ei ht series of tampers, a single cam 155 is provided to actuate all of the valves of each series as they move into down position, as shown in FIGURE 10. The valves 1% are provided with compressed return springs 110, shown in FIGURE 9. They normally urge the valve stems inwardly in the direction of the axle C. Some stop means (not shown) may be provided to limit the travel of the valve stems so far as the inward position is concerned, such as a groove in the valve stem and a pin on the valve sleeve, in order that the springs may always be maintained under compression and the inner ends of the valve stems will not hit the axle C, but only the cam 105.

Each valve 1% is provided with a reduced intake portion and a similarly reduced outlet portion 116. As shown in FIGURE 9 the valve stem 101 has been depressed by the cam 105 so that the intake port 115 of the valve aligns with the passageway 83 and port 34 to permit the actuating fluid to enter the top of the cylinder chamber 66 above the piston. When the spring 110 returns the valve stem to normal position, after passing the cam the exhaust port of reduced portion 116 will align the port 86 with the exhaust passageway 35 of the valve housing and permit the fluid to be exhausted under impetus of the tamping head spring 63.

Referring to the developed view of the drum 45, shown in FIGURE 4, it will be noted that the eight series of tampers have the heads for each series located in the plane of the drum. However, the tamping heads for the different series are out of transverse alignment upon the drum, in order that less than the full number of tamping heads for the entire series will be actuated at the same time. As shown, and again referring to FIGURES l and 4, the tamping heads 6%, 69 63 and 69% are diagonally arranged from the central plane of the drum transversely of the drum, and the complementary tamping head 65 65 61% and 60 are likewise arranged but in acute angled or opposite diagonal position. With this arrangement only two tamping heads of each drum are in tamping position at any one time. That is the tamping heads 69 and 66*, or the tamping heads 6% and 60 or the tamping heads 60 and 65 or the tamping heads 65 and 65 are in effective position.

The air compressor G is mounted upon the beams 23 as shown in FIGURES 1 and 2 and it has the hose connections 37 mounted upon the frame and leading to the outer ends of the respective axles C of the two rollers D.

All parts of the machine are of rigid materials, preferably metal, with the exception of the hose portions 94. Of course, travel of the implement over the ground surface through draft from the tractor will rotate the drums E and through connections of the valve sleeves 102 and the hose 94 with the air rings 90 the latter will be rotated in bearing relation upon the cylindrical axle portions 32 For a five foot diameter roller drum I have found that an air compression of 150 pounds per square inch will be suflicient to operate tamping heads having a seven inch stroke with individual outer tamping areas of seven square inches. These dimensions are not critical but may be departed from depending upon the type of material or soil to be tamped.

In order to point out the advantages of the invention over conventional tamping equipment, using an air pressure of 150 pounds per square inch tamping surface, each piston will produce 612.5 foot-pounds per revolution of the drum and 112 pistons will produce a total of 68,600 foot-pounds compactive effort per revolution of the drum. Using a five foot diameter drum five feet long such will cover 86 square feet of surface area and 43 cubic feet of material in one revolution thereby producing approximately 1600 foot-pounds of energy per cubic foot of material per roller pass. The improved tamping machine of the present invention will require approximately 8 passes over a given area to duplicate the standard compactive effort of conventional tamping machines which require 12,375 foot-pounds of energy per cubic foot and 12. passes to accomplish the same result. In addition, by reason of fluid activation of the tamping feet, the improved machine requires less weight for compactive effort, less draw-bar horsepower, and fewer passes over a given area and operates with greater speed.

Various changes in the shape, size, and arrangement of parts may be made to the form of the invention herein shown and described without departing from the spirit of the invention or the scope of the claims.

I claim:

1. In an impact tamping machine the combination of a supporting frame, an axle mounted on the frame against rotation, a roller mounted upon said axle comprising a drum having an outer cylindrical wall, cylinders radially mounted upon said wall opening at their outer ends upon said wall, piston and tamping head means in each of said cylinders slidably mounted therein, means normally retnacting the tamping heads in the respective cylinders, valve means mounted upon said cylinders, means for directing a pressure fluid .through the valve means into and out of said cylinders, and cam means mounted on the axle for actuating said valve means as the roller rotates upon said axle.

2. In an impact tamping machine the combination of a supporting frame, a stationary axle nonrotatably mounted upon said frame a roller rotatably mounted on the axle, said roller including an outer drum wall, a plurality of cylinders supported upon said drum wall having chambers therein opening outwardly upon said wall, piston and tamping means mounted slidably in each of said cylinders, actuating fluid pressure providing means, valve means associated with each of said cylinders for admitting and exhausting the actuating fluid with respect to the cylinders for actuating said tamping heads, and cam means on said axle for actuating said valve means.

3. In an impact tamping machine the combination of a supporting frame, a stationary axle mounted on the frame, a roller drum mounted upon said axle, a plurality of side by side located series of tempers slidably mounted upon said drum for withdrawable peripheral extension therefrom, each series comprising a plurality of tampers disposed in the same vertical plane, pressure fluid actuating means, valve means mounted on the drum for each of said tampers of each of said series for supplying the activating fluid to said tampers, and cam means on said axle for operating the valve means.

4. In an impact tamping machine the combination of a supporting frame, an axle nonrotatably mounted upon said frame having a passageway axially therethrough,

means for feeding fluid through said passageway under pressure, fluid distributing means rotatably mounted upon said axle, a drum rotatably mounted on said axle having an outer peripheral wall and having the fluid distributing means disposed therein, the passageway of the axle having port means open from said distributing means for admission of fluid pressure thereto, a plurality of cylinders mounted upon the outer wall of said drum, a tarnping head and piston slidably mounted in each of said cylinders, valve means for directing fluid pressure from said fluid distributing means to said cylinders for actuating the pistons and tamping heads therein, and cam means mounted on said axle for controlling the opening and closing of the valve means.

5. An impact tamping machine as described in claim 4 in which the piston and tamping heads within their respective cylinders are provided with spring means normally retracting them within the respective cylinders.

6. In an impact t amping machine the combination of a supporting frame, an axle nonrotataoly mounted upon the frame, a roller drum having side walls rotatably hearing on said axle and including an outer cylindrical wall, a series of cylinders radially mounted upon said outer wall having chambers therein opening outwardly from said outer wall, a piston and tamping head mounted in each of said cylinders slidably therein for projection and retraction with respect to said outer wall, spring means normally retracting the pistons and tamping heads with respect to their respective cylinders, a series of fluid distributing rings rotatably mounted upon said axle located within the drum and each having fluid receiving chambers therein, means for supplying actuating fluid to said rings, means connecting the distributing rings with the respective series of cylinders for supplying the actuating fluids to said cylinders including valve means mounted on said cylinders for controlling admission and exhaustion of the actuating fluid to the cylinders, and cam means on said axle for operating said valve means as the drum rotates around said axle.

7. An impact tamping machine as described in claim 6 in which each distributing ring has located in the same plane therewith a plurality of said cylinders and their tamping heads arranged radially upon the outer wall of the drum and in which the tamping heads for one distributing ring are arranged on said drum outer well out of direct right angled transverse alignment on the wall with respect to the tamping heads of adjacent distributing rings.

8. In an impact tamping machine the combination of a supporting frame, a plurality of stationary axles mounted upon the frame in axially aligned relation, a cylindrical drum rotatably mounted on each of said axles, a plurality of cylinders mounted radially on each of said drums, tamping heads and pistons slidably mounted in said cylinders, spring means normally retracting the tamping heads and pistons into said cylinders, the cylinders being opened upon said drums whereby the same may be extended from the peripheries of the drums for tamping purposes, valve means mounted on each of said cylinders, means for supplying fluid pressure to each of said valve means, and cam means mounted on said stationary axles for actuating the valve means at predetermined locations during the rotation of the drums.

9. In an impact tamping machine the combination of a supporting frame, an axle non-rotatably mounted upon the frame, a roller drum having side walls rotatably bearing on the axle and an outer cylindrical wall, a series of cylinders radially mounted upon said outer wall having chambers therein opening outwardly from said outer drum wall, a piston and tamping head mounted in each of said cylinders slidable therein for projection and retraction with respect to said outer drum wall, spring means nor mally retracting the pistons and tamping heads, a series of fluid distributing rings rotatably mounted on the axle located Within the drum and each having a fluid receiving chamber therein, means mounted on the frame for supplying pressure fiuid to said rings, means connecting the distributing rings with the respective series of cylinders for supplying actuating fluid to said cylinders, valve means mounted on each cylinder for controlling admission and exhaustion of the actuating fluid to the cylinder, and a single cam for each distributing ring mounted on the axle beside each distributing ring for operating the valve means of the cylinders in sequential action.

524,536 Youtz Aug. 14, 1894 8 Wegener Sept. 10, 1912 Dunham July 4, 1916 Gratton Aug. 21, 1917 Jacobson July 21, 1936 Wiegand Aug. 17, 1937 P ararnythioti Apr. 6, 1954 Gardner July 17, 1956 FOREIGN PATENTS Denmark Feb. 13, 1928 Great Britain Aug. 9, 1950 OTHER REFERENCES Road & Engineering Construction, October 1954, p. 90.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,114,305 December 17, 1963 Frederick J. Davis It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 64, after column 6, lines 60 and 61, for

"drum" insert rotatably "valve means" read cylinders Signed and sealed this 28th day of April 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J" BRENNER 

1. IN AN IMPACT TAMPING MACHINE THE COMBINATION OF A SUPPORTING FRAME, AN AXLE MOUNTED ON THE FRAME AGAINST ROTATION, A ROLLER MOUNTED UPON SAID AXLE COMPRISING A DRUM HAVING AN OUTER CYLINDRICAL WALL, CYLINDERS RADIALLY MOUNTED UPON SAID WALL OPENING AT THEIR OUTER ENDS UPON SAID WALL, PISTON AND TAMPING HEAD MEANS IN EACH OF SAID CYLINDERS SLIDABLY MOUNTED THEREIN, MEANS NORMALLY RETRACTING THE TAMPING HEADS IN THE RESPECTIVE CYLINDERS, VALVE MEANS MOUNTED UPON SAID CYLINDERS, MEANS FOR DIRECTING A PRESSURE FLUID THROUGH THE VALVE MEANS INTO AND OUT OF SAID CYLINDERS, AND CAM MEANS MOUNTED ON THE AXLE FOR ACTUATING SAID VALVE MEANS AS THE ROLLER ROTATES UPON SAID AXLE. 